Koi growth- early vs late vs final size

[Spike Cover]

All,

Sorry if I'm bringing a subject that has already been thrashed-out/over/whatever here.

Regarding the subject, I think I know that the "general wisdome" within the koi cummuinty says that if fish are big early in life, that they will likely be bigger later in life. This applies to the "jumbo tosai" we all see in the shops - and pay more for.

But I believe I have seen (can't remember where) that some respected breeders (probably from the colder country, i.e., Niigata) have said that fish grow as big or bigger eventually if they are not forced (implying forced in warm water during times that warm water does not naturally occure) even though they grow slower. And, it is said that these "slow grown" fish are healthier in general.

I've spent that last several years trying to figure out how to keep them alive and well. I'm thinking about turning my attention to what most call "koi appreciation" (after McGill).

I know a lot of the knowledge in Japan is gained thru the school of hard knocks and is maybe not all that scientific. I still respect that and believe it's valuable.

I have found some evidence that maybe growing them slow and in colder water makes bigger fish eventually. See attached abstract.

So, without hopefully starting any flame wars, can any of you add anything, scientific or otherwise, to this topic? (or point me to the thread where it was already discussed when I wasn't here).

All the best,
Spike Cover

[dick benbow]

I quess over the time I've been involved in koi, I have heard all of the urban legends around. The last coupla decades rather than believe what I read or hear, I've been busy learning on my own. Different filter media, different food,different bloodlines, yes even jumbo tosai. So I quess what I'm about to say is from my own learning experience. I have a relatively small pond, so I run a meager amount of koi in my system to compensate. Those that I pushed the first three years of their life believing this was the time to capture maximum length without the sexual maturity concerns met my expectations. Those that I pushed in season and allowed to slow in winter
easily caught up with the others. I have had koi which were labeled as refusing to grow in friend's ponds, take off in mine for a season. Because of my high regard for toshio sakai, most of all my koi are matsunosuke bloodline.
I have friends who claim that fish raised elsewhere that were pushed appeared to have health issues later in life.Is it just their ponds? I don't know. Since buying 3 and 4 year old koi is out of the realm of my budget, my experiences have been with tosai.
My hunch is that there is a price to be paid for pushing the envelope. How many Sumo wrestlers live a long and health concern free life? The other side of the coin ( or for the samerai out there, the other edge of the sword) is that if I was a breeder who's livlihood
depended on getting their contestants up to task in 5 years to compete in the show of shows, I might look at this different ! For me I'm perfectly happy to provide the best of everything for my charges with the expectation that allowing them to live a long and happy life being the best they can be fits best with where I am in the hobby.

[Louie]

I read not too long ago that tosai should be kept in warmer water and fed through out the year. Perhaps it is just to help them gain strength and get them thru the baby stage. I have found like so many that fasting koi 15" and up for a few monthes does not stop their growth in cold weather. That time out they get only helps boost their appetite when I start feeding again. So I guess that is more of a natural yearly cycle for them. It gives them a chance to rest. I also slow down water current just for that same reason. My fish do not stay at the bottom of the pond they just swim at their leisure and eat alge.
Louie

[Mtn ponder]

Hi Dick, can you help define what you define as being pushed. I take this to mean warm water year round and a lot of high growth food.

[PapaBear]

I wholeheartedly agree with Dicks observations.

Even if we look only to the Japanese breeders for guidance, we see breeders from all climate regions producing Koi of similar bloodlines to the same size at full maturity. Some make heavy use of heated greenhouses, others deep mudponds for overwintering. Time and a healthy environment for Koi allow them to reach their genetic potential.

There are plenty of examples, although a few are a bit extreme.
Body builders for example will reach a "plateau" of sorts, and when they do they often shift their workout routine to break through to new building of mass. More and Heavier weights aren't always the answer though. Quite often it is less weight and more repetitions. It sounds a bit like Dicks example of Koi that had stopped growing in one pond hitting a fresh spurt when placed in a new environment. It may not mean that the old environment was "bad" per-se, only that a change was needed to encourage a metabolic awakening.

Last year we observed that some of our fish merely maintained themselves during the winter fast, growing maybe 1/4"-1/2", while others added surprising length even as they slimmed down. Their individual genetics are the only possible determining factor, as they were all in the same pond, fed the same way up to the beginning of the fast, and had the same environment throughout.

[111whalen]

Spike-nice to see you on Bito. Your background and interest in the hobby needs to be seen on this board. Dick, I have only had one jumbo toasi and it has grown slowly since becoming two. The theory in Spike's starter would explain why Northern Japenese fish catch up with the South. Louie, on another thread a Florida keeper thought all So Cal experts feed all year. You have joined the strategy of fasting, which I use. I did talk to a friend who fasted for 3 month last year in So Cal and she felt it did have a negative impact on the bodies of her fish. It seems we are all experimenting-each year is different; and then you add the pond, filter, fish....

[Louie]

The negative results your friend could have had maybe due to not pumping them up during growing season. I am amazed that she did not get better confirmation on her females . My males coming out of winter still have decent confirmation. Feed, feed , feed during growing season. Small quanity often. The last two years I have used a demand feeder from AES it works very well and is adjustable.
One other thing that I failed to mention is water changes even tho they are not eating prepared food they eat alge so I still change 15% water every week and add clay. I think those water changes are what keeps the shirogi up on my fish summer,fall,winter, spring. 30% water changes during growing season without fail.
Louie

[B.Scott]

Interesting read Spike. Now I wonder if delaying the time it takes for a fish to reach maximum size would correlate with the peak of it's development qua sumi and beni? It would be sad if the fish reaches the peak in it's pattern Before or after reaching optimum size. Could be a mixed blessing.

B.Scott

[schildkoi]

Intere3sting subject and "controversy." A Koi's "potential" for size is one of pure genetics. His ability to reach that potential is another story. Environment and diet come into play here. By forcing the environment and diet, perhaps one can quicken the rise to its size potential but as mentioned, at what health costs? I am not a fish pysiologist so I really can't say about that. Koi, like other animals wil vary in their rate of growth even under the same gentic size potential and environment/diet since all are different in other ways. Look at it this way, were the bigger kids in grade school always remain the bigger kids by the end of high school?

Now, from a show perspective there may be some advantage to forcing growth at an early age. Having a large, yourthful koi does have its advantages over having a large old koi from a skin and color perspective. BUT, forcing groth too much can also have adverse effects in this area as well. Ever see a koi fed too much high protien paste food? Rouch skin and faded beni are a few visible signs of this.

Just throwing out some food for thought. I'll stick with my 4 season varible season diet for my koi.

Steve

[dick benbow]

Those with genetically predisposed ability to grow are kept from tosai on, in heated winter facilities and minimally stocked mudponds and pushed thru the first 3 winters as well as summers to gain maximum growth. Because of sexual maturity (females) at 3-4 they then are slowed in winter to allow for reabsorption of the egg protein and then selected for the mud pond that best suits their needs, protected beni, developing sumi etc. By the age of 5 they are atleast 80 cm plus, many these days are 90 cm.

But along the way, many shiro muji and shiro bekko and shiro utsuri emerge
where kohaku,sanke and showa were oririginally stocked. But breeders and top end hobbists who entrust their possible national koi into their hands accept that under the best of conditions you can still have losses. It's acceptable in the quest for the best. It is my opinion that many of these koi that were pushed could have developed later and NOT lost their color. A big young fibrant koi full of life exzudes what the judges are looking for.

In bonsai there is a trend these days to take a tree and do a complete makeover so that it goes from being a prospect to finished bonsai in one season. Some accept this and others want to do one portion per year so as always to maintain the health of the subject. It may take several years but the shock of a one year treatment is averted.
your finances, your quest, your patience or lack there of and your philosophy all combine into making koi keepers ( or bonsai) comfortable in which application they choose. For me, All the years I studied the japanese culture, I admired the respect for age and the ability to have patience. But then nothing stays the same and ultimately it comes down to our choice.